What is Astrocytoma?
Astrocytoma is a form of brain tumor that begins in astrocytes—star-shaped glial cells that provide essential structural and functional support to the neurons within the brain and spinal cord. When mutations or genetic alterations occur, these cells may begin to multiply uncontrollably, ultimately leading to the development of a tumor.Types and Classification of Astrocytoma
1. Astrocytoma, IDH-Mutant (Adult-Type Diffuse Gliomas)
Grade 2: These tumors typically grow at a slower rate and are associated with a relatively favorable prognosis.
Grade 3: Tumors at this stage are more aggressive and were previously classified as anaplastic astrocytoma/astrocytoma anaplastic.
Grade 4: Identified by the presence of homozygous deletion in the CDKN2A/B genes, even if tissue necrosis or vascular proliferation is not evident.
2. Glioblastoma, IDH-Wildtype
Grade 4 by Definition: Glioblastoma is universally categorized as a Grade 4 tumor.
Diagnostic Criteria: Even without histological features like necrosis, molecular markers such as TERT promoter mutations, EGFR gene amplification, or combined chromosomal abnormalities (+7/–10) are sufficient for diagnosis.
3. Pediatric-Type Diffuse Gliomas
Low-Grade Gliomas: Frequently linked to genetic changes involving MYB, MYBL1, or alterations in the MAPK signaling pathway.
High-Grade Gliomas: These include aggressive forms such as H3 K27-altered and H3 G34-mutant gliomas, typically associated with poor clinical outcomes.
4. Circumscribed Astrocytic Tumors
This group encompasses Pilocytic Astrocytoma/Astrocytoma pilocytic (Grade 1), Pleomorphic Xanthoastrocytoma (Grades 2/3), and Subependymal Giant Cell Astrocytoma (Grade 1).
Unlike diffuse gliomas, these tumors often have well-defined margins and generally present a more favorable prognosis.
Common Symptoms of Astrocytoma
The clinical presentation of brain astrocytoma can vary widely depending on the tumor’s size, growth rate, and specific location in the brain. Common symptoms include:Headaches: Typically more intense in the morning and may not respond well to over-the-counter pain medications.
Nausea and Vomiting: Often associated with elevated pressure inside the skull.
Visual Problems: Blurred vision, double vision, or partial vision loss may occur as the tumor affects visual pathways.
Motor Weakness and Coordination Issues: Tumors can impact brain regions responsible for movement, leading to muscle weakness or balance problems.
Seizures: Abnormal electrical activity in the brain triggered by the tumor can result in seizures.
Cognitive and Emotional Changes: Some individuals may experience memory problems, difficulty concentrating, mood swings, depression, or noticeable shifts in personality.
Diagnostic Approaches
Neurological Assessment: Doctors perform comprehensive exams to evaluate reflexes, muscle strength, balance, vision, and language abilities, aiming to detect neurological deficits.
Magnetic Resonance Imaging (MRI): About the astrocytoma radiology: MRI scans are the gold standard for identifying brain tumors, assessing their size, location, and potential spread. Contrast materials are often used to enhance image clarity.
Computed Tomography (CT) Scan: CT imaging may be employed in urgent cases to quickly visualize brain abnormalities, though it typically provides less detail compared to MRI.
Treatment Strategies for Astrocytoma
Astrocytoma brain treatment depends on several factors, including tumor type, size, the patient’s general health, and the severity of symptoms.1. Surgical Intervention
Microsurgical Resection: The primary goal of surgery is to remove as much of the tumor as safely possible. In low-grade astrocytomas, surgical removal can significantly improve outcomes.
Awake Craniotomy: In cases where the tumor is near vital areas responsible for speech or motor functions, surgery may be performed while the patient is awake to ensure critical abilities are preserved.
2. Radiation Therapy
High-energy radiation is used to destroy remaining tumor cells or inhibit their growth, especially when complete surgical removal is not feasible.
3. Chemotherapy
Chemotherapy uses drugs to slow or halt tumor progression. It is often combined with radiation therapy for high-grade or aggressive astrocytomas.
4. Targeted Therapy and Immunotherapy
Emerging treatments focus on targeting specific genetic mutations within tumor cells or enhancing the immune system’s ability to recognize and attack the tumor. These advanced approaches are expanding the options available for managing astrocytomas of brain and improving patient survival.